Safety mine shooting devices



M r 1955 N. MARUSCHAK ET AL SAFETY MINE SHOOTING DEVICES 2 Shee'ts-Sheet 1 Filed Jan. 30 1951 Elma/whoa) Niel: l/aruscha]:

March 15, 1955 N. MARUSCHAK ET AL 2,704,032 Y SAFETY MINE SHOOTING DEVICES Filed Jan. 30, 1951 2 Sheets-Sheet 2 I M'vk Mafusoiz a]: Denver BarZZe $auy7z United States Patent SAFETY MINE SHOOTING DEVICES Nick Maruschak and Denver Bartlebaugh, Mooween, Pa.

Application January 30, 1951, Serial No. 208,592 3 Claims. (Cl. 102-27) This invention relates to new and useful improvements in safety mine shooting devices.

The primary object of our invention is to provide novel means that may be used in connection with the conventional mine shooting cable, whereby the operator is permitted to remove to a safe distance from the danger zone before the shunt is released and the charge of dynamite fired. Without the use of our invention, the shunt must be removed when the operator is near the charge and a stray current from steel rails, water or other equipment can then pass along the shooting cable and explode the charge before the operator can remove himself from the danger zone.

A further object of our invention is to provide a safety mine shooting device of the character specified that is relatively simple and economical in construction and highly efiicient and durable in use.

With the foregoing and other objects in view that will appear as the nature of our invention is better understood, the same consists in the novel features of construction, combination and arrangement of parts illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

In the acompanying drawings, which are for illustrative purposes only and are therefore not drawn to scale;

Fig. l is a side elevation of the device with parts in the position as shown in Fig. 2 or non-firing position,

Fig. 2 is a front elevation, parts in section, with the parts in non-firing position, the dotted lines indicating the position assumed when the device is being fired,

Fig. 3 is an enlarged cross sectional view taken on line 33 of Fig. 2,

Fig. 4 is a diagrammatic view similar to Fig. 2 and illustrating the circuit,

Fig. 5 is a cross sectional view showing details of the wire clamp,

Fig. 6 is a detail view showing the wire gripping action of the spring clamp, and

Fig. 7 is a sectional view of a form of lead wire.

Referring to the drawings for a more particular description of our invention, and in which drawings like parts are designated by like reference characters throughout the several views, the numeral 1 represents the electric cap or detonator, 2 the lead wires of the detonator and 3 the conventional insulated mine shooting cable, comprising two conductors and approximately 125 feet long.

In carrying out our invention, a yoke 4, made in two corresponding half sections 5 and 6 bolted or otherwise fastened together, is used in association with the mine shooting cable 3, and said yoke sections are formed in their inner faces with perpendicular and lateral intersecting and registering grooves 7 and 8, respectively, to receive corresponding portions of the separated end portions 9 and 10 of said cable. The separated end portions 9 and 10 of the mine shooting cable 3, after extending through the grooves 7 and 8 aforesaid, project beyond the outer end of yoke 4, with their outer ends or terminals 11 connected by means of the circuit-making clamps 12 to the inner ends 13 of the lead wires 2 of the detonator 1, the purpose of which will presently apear. p The inner ends of the aforesaid lead wires 2 are formed with the terminal portions 14 of conducting material, which are held in contact with each other by the jaws 15 of the spring controlled clamp 16, suitably fastened to and carried by the yoke 4 to insure electrical contact between said elements. It may be desirable to apply additional elements 14 further removed from the end of the conductor, as shown in Fig. 7.

A fiat substantially U-shaped spring 17 is arranged with its inner or bight portion, as 18, seating in corresponding registering grooves 19 and 20 in the sections 5 and 6 of the yoke 4 and with its end portions 21 attached to the outer terminals 11 of the separated end portions 9 and 10 of the shooting cable 3'. A pull cable 22 is suitably attached at one end, as at 23, to the yoke 4.

In practice, a hole is drilled in the coal or rock to be blasted, and a charge of dynamite placed in the hole, together with the electric cap or detonator 1. Clay or other non-combustible material is then tamped in the hole, with the two lead wires 2 protruding therefrom. The shunt formed by the straight terminal portions 14 of the lead wires 2 is not removed until the operator is permitted to remove a safe distance from the danger zone. The shunt is then removed by exerting a pull on the pull cable 22. This pull action upon cable 22 is transmitted to the spring arm portions 21 through the clamps 12 to the wires 2. The latter are therefore straightened, because of their connection with the charge 1, thus offering resistance to further longitudinal movement, whereupon the yoke 4 exerts: pull upon the jaws 15 of the spring controlled clamp 16 to release the terminal portions 14 of the lead wires 2, which are then instantly separated or forced apart by the outer ends 21 of the spring 17, as illustrated in Figure 2 of the drawings. The shunt being broken current is then allowed to complete the circuit through the lead wires 2 of the detonator 1 and the charge of dynamite is fired by means of a hot shot battery 24 connected to the remote end of the shooting cable 3.

While our safety mine shooting device is primarily designed for mining coal or blasting rock, it may be used to advantage in all kinds of mining and quarrying where blasting is carried out; also, in excavating and the construction of tunnels.

From the foregoing description taken in connection with the drawings, it is thought that the construction, operation and advantages of our invention will be readily understood, without requiring a more extended explanation.

Various changes in the form, proportions and minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of our invention as defined in the appended claims.

Having described our invention, what we claim as new and desire to secure by Letters Patent, is:

l. A safety mine shooting device comprising a yoke, a mine shooting cable having separated conductors at one end carried by and extending beyond said yoke, a detonator having separated lead wires, clamps connecting the separated conductors of the mine shooting cable to the inner ends of said lead wires, a substantially U-shaped spring carried by the yoke and tending to separate the inner ends of said lead wires, a spring controlled clamp carried by the yoke and normally holding the inner ends of said lead wires together and providing a shunt for the current, and means under the control of the operator for releasing said clamp from the inner ends of said lead wires to the influence of said U-shaped spring.

2. A safety mine shooting device comprising a yoke. a mine shooting cable having separated] conductors at one end carried by and extending beyond said yoke, a detonator having separated lead wires, clamps for electrically connecting the separated conductors of the mine shooting cable to the adjacent ends of said lead Wires, a substantially U-shaped spring carried by the yoke and having each of its arms connected to a conductor, a spring controlled clamp carried by the yoke and acting to hold the inner ends of said lead wires together against tension of said spring arms and providing a shunt for the current, and a pull cable connected at one end to said yoke for releasing the jaws of said clamp from the inner Patented Mar. 15, 1955 i 5f $51 l dll liis e n r i p ratio of" the latt By iiifli'ienc'e" of said spring arm.

3. A safety mine shootingzjievice comprising a yoke, a mine shooting cable having separated conductors aton "'arrij'ed byand extending b'eyond 'sa'id yoke, a' detoy able liayiir'gfseparafed lead Wiresjforr'ned with termmaPbbr'tions, chim s for. co'nnecting 'thfe outer ends of the separated conductors of the mine" sli'ootirig'. lcalile" t'o the inner ends of, said lead wires'at'points1 adjacent to Buy Beyond. said: terminal portibn'sg, a .5l bstan'tially U-s'ha'pd spring 'ca'iriediby' they'oke' and arranged WithIits end portions connected tothe outer ends of the separated conductors of the mine shooting cable; said spring tendiirg tirspzirate the inner ends' of said lead wires, 2:-

.7 spring controlled clamp cam d by said y oke said clamp Having co ac'tiii'g ja'vis'iiorifi'aHy efiga ihg ariamolamg the contacting terminal poritions of said lead wires together and to tension said spring arms and provide a shunt for the current, and a pull cable connected at one end to said yoke for releasing the jaws of the spring controlled clamp from said terminaLportions to permit separation of the latter by release of said tensioned spring arms.

kefermc'e eited imthe-fileiof this: patent UNLIED STATES PATENTS: 1,897,685 Williams et al Feb. 14, 1933 

